drivers/s390/cio/device.c

   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/errno.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/device.h>
  18 #include <linux/workqueue.h>
  19 #include <linux/timer.h>
  20
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/param.h>          /* HZ */
  24 #include <asm/cmb.h>
  25 #include <asm/isc.h>
  26
  27 #include "chp.h"
  28 #include "cio.h"
  29 #include "cio_debug.h"
  30 #include "css.h"
  31 #include "device.h"
  32 #include "ioasm.h"
  33 #include "io_sch.h"
  34
  35 static struct timer_list recovery_timer;
  36 static DEFINE_SPINLOCK(recovery_lock);
  37 static int recovery_phase;
  38 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  39
  40 /******************* bus type handling ***********************/
  41
  42 /* The Linux driver model distinguishes between a bus type and
  43  * the bus itself. Of course we only have one channel
  44  * subsystem driver and one channel system per machine, but
  45  * we still use the abstraction. T.R. says it's a good idea. */
  46 static int
  47 ccw_bus_match (struct device * dev, struct device_driver * drv)
  48 {
  49         struct ccw_device *cdev = to_ccwdev(dev);
  50         struct ccw_driver *cdrv = to_ccwdrv(drv);
  51         const struct ccw_device_id *ids = cdrv->ids, *found;
  52
  53         if (!ids)
  54                 return 0;
  55
  56         found = ccw_device_id_match(ids, &cdev->id);
  57         if (!found)
  58                 return 0;
  59
  60         cdev->id.driver_info = found->driver_info;
  61
  62         return 1;
  63 }
  64
  65 /* Store modalias string delimited by prefix/suffix string into buffer with
  66  * specified size. Return length of resulting string (excluding trailing '\0')
  67  * even if string doesn't fit buffer (snprintf semantics). */
  68 static int snprint_alias(char *buf, size_t size,
  69                          struct ccw_device_id *id, const char *suffix)
  70 {
  71         int len;
  72
  73         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  74         if (len > size)
  75                 return len;
  76         buf += len;
  77         size -= len;
  78
  79         if (id->dev_type != 0)
  80                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  81                                 id->dev_model, suffix);
  82         else
  83                 len += snprintf(buf, size, "dtdm%s", suffix);
  84
  85         return len;
  86 }
  87
  88 /* Set up environment variables for ccw device uevent. Return 0 on success,
  89  * non-zero otherwise. */
  90 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  91 {
  92         struct ccw_device *cdev = to_ccwdev(dev);
  93         struct ccw_device_id *id = &(cdev->id);
  94         int ret;
  95         char modalias_buf[30];
  96
  97         /* CU_TYPE= */
  98         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
  99         if (ret)
 100                 return ret;
 101
 102         /* CU_MODEL= */
 103         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 104         if (ret)
 105                 return ret;
 106
 107         /* The next two can be zero, that's ok for us */
 108         /* DEV_TYPE= */
 109         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 110         if (ret)
 111                 return ret;
 112
 113         /* DEV_MODEL= */
 114         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 115         if (ret)
 116                 return ret;
 117
 118         /* MODALIAS=  */
 119         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 120         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 121         return ret;
 122 }
 123
 124 struct bus_type ccw_bus_type;
 125
 126 static void io_subchannel_irq(struct subchannel *);
 127 static int io_subchannel_probe(struct subchannel *);
 128 static int io_subchannel_remove(struct subchannel *);
 129 static void io_subchannel_shutdown(struct subchannel *);
 130 static int io_subchannel_sch_event(struct subchannel *, int);
 131 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 132                                    int);
 133
 134 static struct css_device_id io_subchannel_ids[] = {
 135         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 136         { /* end of list */ },
 137 };
 138 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 139
 140 static struct css_driver io_subchannel_driver = {
 141         .owner = THIS_MODULE,
 142         .subchannel_type = io_subchannel_ids,
 143         .name = "io_subchannel",
 144         .irq = io_subchannel_irq,
 145         .sch_event = io_subchannel_sch_event,
 146         .chp_event = io_subchannel_chp_event,
 147         .probe = io_subchannel_probe,
 148         .remove = io_subchannel_remove,
 149         .shutdown = io_subchannel_shutdown,
 150 };
 151
 152 struct workqueue_struct *ccw_device_work;
 153 wait_queue_head_t ccw_device_init_wq;
 154 atomic_t ccw_device_init_count;
 155
 156 static void recovery_func(unsigned long data);
 157
 158 static int __init
 159 init_ccw_bus_type (void)
 160 {
 161         int ret;
 162
 163         init_waitqueue_head(&ccw_device_init_wq);
 164         atomic_set(&ccw_device_init_count, 0);
 165         setup_timer(&recovery_timer, recovery_func, 0);
 166
 167         ccw_device_work = create_singlethread_workqueue("cio");
 168         if (!ccw_device_work)
 169                 return -ENOMEM; /* FIXME: better errno ? */
 170         slow_path_wq = create_singlethread_workqueue("kslowcrw");
 171         if (!slow_path_wq) {
 172                 ret = -ENOMEM; /* FIXME: better errno ? */
 173                 goto out_err;
 174         }
 175         if ((ret = bus_register (&ccw_bus_type)))
 176                 goto out_err;
 177
 178         ret = css_driver_register(&io_subchannel_driver);
 179         if (ret)
 180                 goto out_err;
 181
 182         wait_event(ccw_device_init_wq,
 183                    atomic_read(&ccw_device_init_count) == 0);
 184         flush_workqueue(ccw_device_work);
 185         return 0;
 186 out_err:
 187         if (ccw_device_work)
 188                 destroy_workqueue(ccw_device_work);
 189         if (slow_path_wq)
 190                 destroy_workqueue(slow_path_wq);
 191         return ret;
 192 }
 193
 194 static void __exit
 195 cleanup_ccw_bus_type (void)
 196 {
 197         css_driver_unregister(&io_subchannel_driver);
 198         bus_unregister(&ccw_bus_type);
 199         destroy_workqueue(ccw_device_work);
 200 }
 201
 202 subsys_initcall(init_ccw_bus_type);
 203 module_exit(cleanup_ccw_bus_type);
 204
 205 /************************ device handling **************************/
 206
 207 /*
 208  * A ccw_device has some interfaces in sysfs in addition to the
 209  * standard ones.
 210  * The following entries are designed to export the information which
 211  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 212  * are obvious, so they don't have an entry :)
 213  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 214  */
 215 static ssize_t
 216 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 217 {
 218         struct subchannel *sch = to_subchannel(dev);
 219         struct chsc_ssd_info *ssd = &sch->ssd_info;
 220         ssize_t ret = 0;
 221         int chp;
 222         int mask;
 223
 224         for (chp = 0; chp < 8; chp++) {
 225                 mask = 0x80 >> chp;
 226                 if (ssd->path_mask & mask)
 227                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 228                 else
 229                         ret += sprintf(buf + ret, "00 ");
 230         }
 231         ret += sprintf (buf+ret, "\n");
 232         return min((ssize_t)PAGE_SIZE, ret);
 233 }
 234
 235 static ssize_t
 236 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 237 {
 238         struct subchannel *sch = to_subchannel(dev);
 239         struct pmcw *pmcw = &sch->schib.pmcw;
 240
 241         return sprintf (buf, "%02x %02x %02x\n",
 242                         pmcw->pim, pmcw->pam, pmcw->pom);
 243 }
 244
 245 static ssize_t
 246 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 247 {
 248         struct ccw_device *cdev = to_ccwdev(dev);
 249         struct ccw_device_id *id = &(cdev->id);
 250
 251         if (id->dev_type != 0)
 252                 return sprintf(buf, "%04x/%02x\n",
 253                                 id->dev_type, id->dev_model);
 254         else
 255                 return sprintf(buf, "n/a\n");
 256 }
 257
 258 static ssize_t
 259 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 260 {
 261         struct ccw_device *cdev = to_ccwdev(dev);
 262         struct ccw_device_id *id = &(cdev->id);
 263
 264         return sprintf(buf, "%04x/%02x\n",
 265                        id->cu_type, id->cu_model);
 266 }
 267
 268 static ssize_t
 269 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 270 {
 271         struct ccw_device *cdev = to_ccwdev(dev);
 272         struct ccw_device_id *id = &(cdev->id);
 273         int len;
 274
 275         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 276
 277         return len > PAGE_SIZE ? PAGE_SIZE : len;
 278 }
 279
 280 static ssize_t
 281 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 282 {
 283         struct ccw_device *cdev = to_ccwdev(dev);
 284
 285         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 286 }
 287
 288 int ccw_device_is_orphan(struct ccw_device *cdev)
 289 {
 290         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 291 }
 292
 293 static void ccw_device_unregister(struct ccw_device *cdev)
 294 {
 295         if (test_and_clear_bit(1, &cdev->private->registered))
 296                 device_del(&cdev->dev);
 297 }
 298
 299 static void ccw_device_remove_orphan_cb(struct device *dev)
 300 {
 301         struct ccw_device *cdev = to_ccwdev(dev);
 302
 303         ccw_device_unregister(cdev);
 304         put_device(&cdev->dev);
 305 }
 306
 307 static void ccw_device_remove_sch_cb(struct device *dev)
 308 {
 309         struct subchannel *sch;
 310
 311         sch = to_subchannel(dev);
 312         css_sch_device_unregister(sch);
 313         /* Reset intparm to zeroes. */
 314         sch->schib.pmcw.intparm = 0;
 315         cio_modify(sch);
 316         put_device(&sch->dev);
 317 }
 318
 319 static void
 320 ccw_device_remove_disconnected(struct ccw_device *cdev)
 321 {
 322         unsigned long flags;
 323         int rc;
 324
 325         /*
 326          * Forced offline in disconnected state means
 327          * 'throw away device'.
 328          */
 329         if (ccw_device_is_orphan(cdev)) {
 330                 /*
 331                  * Deregister ccw device.
 332                  * Unfortunately, we cannot do this directly from the
 333                  * attribute method.
 334                  */
 335                 spin_lock_irqsave(cdev->ccwlock, flags);
 336                 cdev->private->state = DEV_STATE_NOT_OPER;
 337                 spin_unlock_irqrestore(cdev->ccwlock, flags);
 338                 rc = device_schedule_callback(&cdev->dev,
 339                                               ccw_device_remove_orphan_cb);
 340                 if (rc)
 341                         CIO_MSG_EVENT(0, "Couldn't unregister orphan "
 342                                       "0.%x.%04x\n",
 343                                       cdev->private->dev_id.ssid,
 344                                       cdev->private->dev_id.devno);
 345                 return;
 346         }
 347         /* Deregister subchannel, which will kill the ccw device. */
 348         rc = device_schedule_callback(cdev->dev.parent,
 349                                       ccw_device_remove_sch_cb);
 350         if (rc)
 351                 CIO_MSG_EVENT(0, "Couldn't unregister disconnected device "
 352                               "0.%x.%04x\n",
 353                               cdev->private->dev_id.ssid,
 354                               cdev->private->dev_id.devno);
 355 }
 356
 357 /**
 358  * ccw_device_set_offline() - disable a ccw device for I/O
 359  * @cdev: target ccw device
 360  *
 361  * This function calls the driver's set_offline() function for @cdev, if
 362  * given, and then disables @cdev.
 363  * Returns:
 364  *   %0 on success and a negative error value on failure.
 365  * Context:
 366  *  enabled, ccw device lock not held
 367  */
 368 int ccw_device_set_offline(struct ccw_device *cdev)
 369 {
 370         int ret;
 371
 372         if (!cdev)
 373                 return -ENODEV;
 374         if (!cdev->online || !cdev->drv)
 375                 return -EINVAL;
 376
 377         if (cdev->drv->set_offline) {
 378                 ret = cdev->drv->set_offline(cdev);
 379                 if (ret != 0)
 380                         return ret;
 381         }
 382         cdev->online = 0;
 383         spin_lock_irq(cdev->ccwlock);
 384         ret = ccw_device_offline(cdev);
 385         if (ret == -ENODEV) {
 386                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
 387                         cdev->private->state = DEV_STATE_OFFLINE;
 388                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 389                 }
 390                 spin_unlock_irq(cdev->ccwlock);
 391                 return ret;
 392         }
 393         spin_unlock_irq(cdev->ccwlock);
 394         if (ret == 0)
 395                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 396         else {
 397                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 398                               "device 0.%x.%04x\n",
 399                               ret, cdev->private->dev_id.ssid,
 400                               cdev->private->dev_id.devno);
 401                 cdev->online = 1;
 402         }
 403         return ret;
 404 }
 405
 406 /**
 407  * ccw_device_set_online() - enable a ccw device for I/O
 408  * @cdev: target ccw device
 409  *
 410  * This function first enables @cdev and then calls the driver's set_online()
 411  * function for @cdev, if given. If set_online() returns an error, @cdev is
 412  * disabled again.
 413  * Returns:
 414  *   %0 on success and a negative error value on failure.
 415  * Context:
 416  *  enabled, ccw device lock not held
 417  */
 418 int ccw_device_set_online(struct ccw_device *cdev)
 419 {
 420         int ret;
 421
 422         if (!cdev)
 423                 return -ENODEV;
 424         if (cdev->online || !cdev->drv)
 425                 return -EINVAL;
 426
 427         spin_lock_irq(cdev->ccwlock);
 428         ret = ccw_device_online(cdev);
 429         spin_unlock_irq(cdev->ccwlock);
 430         if (ret == 0)
 431                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 432         else {
 433                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 434                               "device 0.%x.%04x\n",
 435                               ret, cdev->private->dev_id.ssid,
 436                               cdev->private->dev_id.devno);
 437                 return ret;
 438         }
 439         if (cdev->private->state != DEV_STATE_ONLINE)
 440                 return -ENODEV;
 441         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
 442                 cdev->online = 1;
 443                 return 0;
 444         }
 445         spin_lock_irq(cdev->ccwlock);
 446         ret = ccw_device_offline(cdev);
 447         spin_unlock_irq(cdev->ccwlock);
 448         if (ret == 0)
 449                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 450         else
 451                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
 452                               "device 0.%x.%04x\n",
 453                               ret, cdev->private->dev_id.ssid,
 454                               cdev->private->dev_id.devno);
 455         return (ret == 0) ? -ENODEV : ret;
 456 }
 457
 458 static void online_store_handle_offline(struct ccw_device *cdev)
 459 {
 460         if (cdev->private->state == DEV_STATE_DISCONNECTED)
 461                 ccw_device_remove_disconnected(cdev);
 462         else if (cdev->drv && cdev->drv->set_offline)
 463                 ccw_device_set_offline(cdev);
 464 }
 465
 466 static int online_store_recog_and_online(struct ccw_device *cdev)
 467 {
 468         int ret;
 469
 470         /* Do device recognition, if needed. */
 471         if (cdev->id.cu_type == 0) {
 472                 ret = ccw_device_recognition(cdev);
 473                 if (ret) {
 474                         CIO_MSG_EVENT(0, "Couldn't start recognition "
 475                                       "for device 0.%x.%04x (ret=%d)\n",
 476                                       cdev->private->dev_id.ssid,
 477                                       cdev->private->dev_id.devno, ret);
 478                         return ret;
 479                 }
 480                 wait_event(cdev->private->wait_q,
 481                            cdev->private->flags.recog_done);
 482         }
 483         if (cdev->drv && cdev->drv->set_online)
 484                 ccw_device_set_online(cdev);
 485         return 0;
 486 }
 487 static int online_store_handle_online(struct ccw_device *cdev, int force)
 488 {
 489         int ret;
 490
 491         ret = online_store_recog_and_online(cdev);
 492         if (ret)
 493                 return ret;
 494         if (force && cdev->private->state == DEV_STATE_BOXED) {
 495                 ret = ccw_device_stlck(cdev);
 496                 if (ret)
 497                         return ret;
 498                 if (cdev->id.cu_type == 0)
 499                         cdev->private->state = DEV_STATE_NOT_OPER;
 500                 online_store_recog_and_online(cdev);
 501         }
 502         return 0;
 503 }
 504
 505 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 506                              const char *buf, size_t count)
 507 {
 508         struct ccw_device *cdev = to_ccwdev(dev);
 509         int force, ret;
 510         unsigned long i;
 511
 512         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 513                 return -EAGAIN;
 514
 515         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 516                 atomic_set(&cdev->private->onoff, 0);
 517                 return -EINVAL;
 518         }
 519         if (!strncmp(buf, "force\n", count)) {
 520                 force = 1;
 521                 i = 1;
 522                 ret = 0;
 523         } else {
 524                 force = 0;
 525                 ret = strict_strtoul(buf, 16, &i);
 526         }
 527         if (ret)
 528                 goto out;
 529         switch (i) {
 530         case 0:
 531                 online_store_handle_offline(cdev);
 532                 ret = count;
 533                 break;
 534         case 1:
 535                 ret = online_store_handle_online(cdev, force);
 536                 if (!ret)
 537                         ret = count;
 538                 break;
 539         default:
 540                 ret = -EINVAL;
 541         }
 542 out:
 543         if (cdev->drv)
 544                 module_put(cdev->drv->owner);
 545         atomic_set(&cdev->private->onoff, 0);
 546         return ret;
 547 }
 548
 549 static ssize_t
 550 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 551 {
 552         struct ccw_device *cdev = to_ccwdev(dev);
 553         struct subchannel *sch;
 554
 555         if (ccw_device_is_orphan(cdev))
 556                 return sprintf(buf, "no device\n");
 557         switch (cdev->private->state) {
 558         case DEV_STATE_BOXED:
 559                 return sprintf(buf, "boxed\n");
 560         case DEV_STATE_DISCONNECTED:
 561         case DEV_STATE_DISCONNECTED_SENSE_ID:
 562         case DEV_STATE_NOT_OPER:
 563                 sch = to_subchannel(dev->parent);
 564                 if (!sch->lpm)
 565                         return sprintf(buf, "no path\n");
 566                 else
 567                         return sprintf(buf, "no device\n");
 568         default:
 569                 /* All other states considered fine. */
 570                 return sprintf(buf, "good\n");
 571         }
 572 }
 573
 574 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 575 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 576 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 577 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 578 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 579 static DEVICE_ATTR(online, 0644, online_show, online_store);
 580 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 581
 582 static struct attribute *io_subchannel_attrs[] = {
 583         &dev_attr_chpids.attr,
 584         &dev_attr_pimpampom.attr,
 585         NULL,
 586 };
 587
 588 static struct attribute_group io_subchannel_attr_group = {
 589         .attrs = io_subchannel_attrs,
 590 };
 591
 592 static struct attribute * ccwdev_attrs[] = {
 593         &dev_attr_devtype.attr,
 594         &dev_attr_cutype.attr,
 595         &dev_attr_modalias.attr,
 596         &dev_attr_online.attr,
 597         &dev_attr_cmb_enable.attr,
 598         &dev_attr_availability.attr,
 599         NULL,
 600 };
 601
 602 static struct attribute_group ccwdev_attr_group = {
 603         .attrs = ccwdev_attrs,
 604 };
 605
 606 static struct attribute_group *ccwdev_attr_groups[] = {
 607         &ccwdev_attr_group,
 608         NULL,
 609 };
 610
 611 /* this is a simple abstraction for device_register that sets the
 612  * correct bus type and adds the bus specific files */
 613 static int ccw_device_register(struct ccw_device *cdev)
 614 {
 615         struct device *dev = &cdev->dev;
 616         int ret;
 617
 618         dev->bus = &ccw_bus_type;
 619
 620         if ((ret = device_add(dev)))
 621                 return ret;
 622
 623         set_bit(1, &cdev->private->registered);
 624         return ret;
 625 }
 626
 627 struct match_data {
 628         struct ccw_dev_id dev_id;
 629         struct ccw_device * sibling;
 630 };
 631
 632 static int
 633 match_devno(struct device * dev, void * data)
 634 {
 635         struct match_data * d = data;
 636         struct ccw_device * cdev;
 637
 638         cdev = to_ccwdev(dev);
 639         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
 640             !ccw_device_is_orphan(cdev) &&
 641             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
 642             (cdev != d->sibling))
 643                 return 1;
 644         return 0;
 645 }
 646
 647 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
 648                                                      struct ccw_device *sibling)
 649 {
 650         struct device *dev;
 651         struct match_data data;
 652
 653         data.dev_id = *dev_id;
 654         data.sibling = sibling;
 655         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
 656
 657         return dev ? to_ccwdev(dev) : NULL;
 658 }
 659
 660 static int match_orphan(struct device *dev, void *data)
 661 {
 662         struct ccw_dev_id *dev_id;
 663         struct ccw_device *cdev;
 664
 665         dev_id = data;
 666         cdev = to_ccwdev(dev);
 667         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 668 }
 669
 670 static struct ccw_device *
 671 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
 672                               struct ccw_dev_id *dev_id)
 673 {
 674         struct device *dev;
 675
 676         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
 677                                 match_orphan);
 678
 679         return dev ? to_ccwdev(dev) : NULL;
 680 }
 681
 682 static void
 683 ccw_device_add_changed(struct work_struct *work)
 684 {
 685         struct ccw_device_private *priv;
 686         struct ccw_device *cdev;
 687
 688         priv = container_of(work, struct ccw_device_private, kick_work);
 689         cdev = priv->cdev;
 690         if (device_add(&cdev->dev)) {
 691                 put_device(&cdev->dev);
 692                 return;
 693         }
 694         set_bit(1, &cdev->private->registered);
 695 }
 696
 697 void ccw_device_do_unreg_rereg(struct work_struct *work)
 698 {
 699         struct ccw_device_private *priv;
 700         struct ccw_device *cdev;
 701         struct subchannel *sch;
 702
 703         priv = container_of(work, struct ccw_device_private, kick_work);
 704         cdev = priv->cdev;
 705         sch = to_subchannel(cdev->dev.parent);
 706
 707         ccw_device_unregister(cdev);
 708         PREPARE_WORK(&cdev->private->kick_work,
 709                      ccw_device_add_changed);
 710         queue_work(ccw_device_work, &cdev->private->kick_work);
 711 }
 712
 713 static void
 714 ccw_device_release(struct device *dev)
 715 {
 716         struct ccw_device *cdev;
 717
 718         cdev = to_ccwdev(dev);
 719         kfree(cdev->private);
 720         kfree(cdev);
 721 }
 722
 723 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 724 {
 725         struct ccw_device *cdev;
 726
 727         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 728         if (cdev) {
 729                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 730                                         GFP_KERNEL | GFP_DMA);
 731                 if (cdev->private)
 732                         return cdev;
 733         }
 734         kfree(cdev);
 735         return ERR_PTR(-ENOMEM);
 736 }
 737
 738 static int io_subchannel_initialize_dev(struct subchannel *sch,
 739                                         struct ccw_device *cdev)
 740 {
 741         cdev->private->cdev = cdev;
 742         atomic_set(&cdev->private->onoff, 0);
 743         cdev->dev.parent = &sch->dev;
 744         cdev->dev.release = ccw_device_release;
 745         INIT_WORK(&cdev->private->kick_work, NULL);
 746         cdev->dev.groups = ccwdev_attr_groups;
 747         /* Do first half of device_register. */
 748         device_initialize(&cdev->dev);
 749         if (!get_device(&sch->dev)) {
 750                 if (cdev->dev.release)
 751                         cdev->dev.release(&cdev->dev);
 752                 return -ENODEV;
 753         }
 754         return 0;
 755 }
 756
 757 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 758 {
 759         struct ccw_device *cdev;
 760         int ret;
 761
 762         cdev = io_subchannel_allocate_dev(sch);
 763         if (!IS_ERR(cdev)) {
 764                 ret = io_subchannel_initialize_dev(sch, cdev);
 765                 if (ret) {
 766                         kfree(cdev);
 767                         cdev = ERR_PTR(ret);
 768                 }
 769         }
 770         return cdev;
 771 }
 772
 773 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
 774
 775 static void sch_attach_device(struct subchannel *sch,
 776                               struct ccw_device *cdev)
 777 {
 778         css_update_ssd_info(sch);
 779         spin_lock_irq(sch->lock);
 780         sch_set_cdev(sch, cdev);
 781         cdev->private->schid = sch->schid;
 782         cdev->ccwlock = sch->lock;
 783         ccw_device_trigger_reprobe(cdev);
 784         spin_unlock_irq(sch->lock);
 785 }
 786
 787 static void sch_attach_disconnected_device(struct subchannel *sch,
 788                                            struct ccw_device *cdev)
 789 {
 790         struct subchannel *other_sch;
 791         int ret;
 792
 793         other_sch = to_subchannel(get_device(cdev->dev.parent));
 794         ret = device_move(&cdev->dev, &sch->dev);
 795         if (ret) {
 796                 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
 797                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 798                               cdev->private->dev_id.devno, ret);
 799                 put_device(&other_sch->dev);
 800                 return;
 801         }
 802         sch_set_cdev(other_sch, NULL);
 803         /* No need to keep a subchannel without ccw device around. */
 804         css_sch_device_unregister(other_sch);
 805         put_device(&other_sch->dev);
 806         sch_attach_device(sch, cdev);
 807 }
 808
 809 static void sch_attach_orphaned_device(struct subchannel *sch,
 810                                        struct ccw_device *cdev)
 811 {
 812         int ret;
 813
 814         /* Try to move the ccw device to its new subchannel. */
 815         ret = device_move(&cdev->dev, &sch->dev);
 816         if (ret) {
 817                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
 818                               "failed (ret=%d)!\n",
 819                               cdev->private->dev_id.ssid,
 820                               cdev->private->dev_id.devno, ret);
 821                 return;
 822         }
 823         sch_attach_device(sch, cdev);
 824 }
 825
 826 static void sch_create_and_recog_new_device(struct subchannel *sch)
 827 {
 828         struct ccw_device *cdev;
 829
 830         /* Need to allocate a new ccw device. */
 831         cdev = io_subchannel_create_ccwdev(sch);
 832         if (IS_ERR(cdev)) {
 833                 /* OK, we did everything we could... */
 834                 css_sch_device_unregister(sch);
 835                 return;
 836         }
 837         spin_lock_irq(sch->lock);
 838         sch_set_cdev(sch, cdev);
 839         spin_unlock_irq(sch->lock);
 840         /* Start recognition for the new ccw device. */
 841         if (io_subchannel_recog(cdev, sch)) {
 842                 spin_lock_irq(sch->lock);
 843                 sch_set_cdev(sch, NULL);
 844                 spin_unlock_irq(sch->lock);
 845                 if (cdev->dev.release)
 846                         cdev->dev.release(&cdev->dev);
 847                 css_sch_device_unregister(sch);
 848         }
 849 }
 850
 851
 852 void ccw_device_move_to_orphanage(struct work_struct *work)
 853 {
 854         struct ccw_device_private *priv;
 855         struct ccw_device *cdev;
 856         struct ccw_device *replacing_cdev;
 857         struct subchannel *sch;
 858         int ret;
 859         struct channel_subsystem *css;
 860         struct ccw_dev_id dev_id;
 861
 862         priv = container_of(work, struct ccw_device_private, kick_work);
 863         cdev = priv->cdev;
 864         sch = to_subchannel(cdev->dev.parent);
 865         css = to_css(sch->dev.parent);
 866         dev_id.devno = sch->schib.pmcw.dev;
 867         dev_id.ssid = sch->schid.ssid;
 868
 869         /*
 870          * Move the orphaned ccw device to the orphanage so the replacing
 871          * ccw device can take its place on the subchannel.
 872          */
 873         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
 874         if (ret) {
 875                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
 876                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
 877                               cdev->private->dev_id.devno, ret);
 878                 return;
 879         }
 880         cdev->ccwlock = css->pseudo_subchannel->lock;
 881         /*
 882          * Search for the replacing ccw device
 883          * - among the disconnected devices
 884          * - in the orphanage
 885          */
 886         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
 887         if (replacing_cdev) {
 888                 sch_attach_disconnected_device(sch, replacing_cdev);
 889                 return;
 890         }
 891         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
 892         if (replacing_cdev) {
 893                 sch_attach_orphaned_device(sch, replacing_cdev);
 894                 return;
 895         }
 896         sch_create_and_recog_new_device(sch);
 897 }
 898
 899 /*
 900  * Register recognized device.
 901  */
 902 static void
 903 io_subchannel_register(struct work_struct *work)
 904 {
 905         struct ccw_device_private *priv;
 906         struct ccw_device *cdev;
 907         struct subchannel *sch;
 908         int ret;
 909         unsigned long flags;
 910
 911         priv = container_of(work, struct ccw_device_private, kick_work);
 912         cdev = priv->cdev;
 913         sch = to_subchannel(cdev->dev.parent);
 914         css_update_ssd_info(sch);
 915         /*
 916          * io_subchannel_register() will also be called after device
 917          * recognition has been done for a boxed device (which will already
 918          * be registered). We need to reprobe since we may now have sense id
 919          * information.
 920          */
 921         if (klist_node_attached(&cdev->dev.knode_parent)) {
 922                 if (!cdev->drv) {
 923                         ret = device_reprobe(&cdev->dev);
 924                         if (ret)
 925                                 /* We can't do much here. */
 926                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 927                                               " %d for 0.%x.%04x\n", ret,
 928                                               cdev->private->dev_id.ssid,
 929                                               cdev->private->dev_id.devno);
 930                 }
 931                 goto out;
 932         }
 933         /*
 934          * Now we know this subchannel will stay, we can throw
 935          * our delayed uevent.
 936          */
 937         sch->dev.uevent_suppress = 0;
 938         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 939         /* make it known to the system */
 940         ret = ccw_device_register(cdev);
 941         if (ret) {
 942                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 943                               cdev->private->dev_id.ssid,
 944                               cdev->private->dev_id.devno, ret);
 945                 put_device(&cdev->dev);
 946                 spin_lock_irqsave(sch->lock, flags);
 947                 sch_set_cdev(sch, NULL);
 948                 spin_unlock_irqrestore(sch->lock, flags);
 949                 kfree (cdev->private);
 950                 kfree (cdev);
 951                 put_device(&sch->dev);
 952                 if (atomic_dec_and_test(&ccw_device_init_count))
 953                         wake_up(&ccw_device_init_wq);
 954                 return;
 955         }
 956         put_device(&cdev->dev);
 957 out:
 958         cdev->private->flags.recog_done = 1;
 959         put_device(&sch->dev);
 960         wake_up(&cdev->private->wait_q);
 961         if (atomic_dec_and_test(&ccw_device_init_count))
 962                 wake_up(&ccw_device_init_wq);
 963 }
 964
 965 static void ccw_device_call_sch_unregister(struct work_struct *work)
 966 {
 967         struct ccw_device_private *priv;
 968         struct ccw_device *cdev;
 969         struct subchannel *sch;
 970
 971         priv = container_of(work, struct ccw_device_private, kick_work);
 972         cdev = priv->cdev;
 973         sch = to_subchannel(cdev->dev.parent);
 974         css_sch_device_unregister(sch);
 975         /* Reset intparm to zeroes. */
 976         sch->schib.pmcw.intparm = 0;
 977         cio_modify(sch);
 978         put_device(&cdev->dev);
 979         put_device(&sch->dev);
 980 }
 981
 982 /*
 983  * subchannel recognition done. Called from the state machine.
 984  */
 985 void
 986 io_subchannel_recog_done(struct ccw_device *cdev)
 987 {
 988         struct subchannel *sch;
 989
 990         if (css_init_done == 0) {
 991                 cdev->private->flags.recog_done = 1;
 992                 return;
 993         }
 994         switch (cdev->private->state) {
 995         case DEV_STATE_NOT_OPER:
 996                 cdev->private->flags.recog_done = 1;
 997                 /* Remove device found not operational. */
 998                 if (!get_device(&cdev->dev))
 999                         break;
1000                 sch = to_subchannel(cdev->dev.parent);
1001                 PREPARE_WORK(&cdev->private->kick_work,
1002                              ccw_device_call_sch_unregister);
1003                 queue_work(slow_path_wq, &cdev->private->kick_work);
1004                 if (atomic_dec_and_test(&ccw_device_init_count))
1005                         wake_up(&ccw_device_init_wq);
1006                 break;
1007         case DEV_STATE_BOXED:
1008                 /* Device did not respond in time. */
1009         case DEV_STATE_OFFLINE:
1010                 /*
1011                  * We can't register the device in interrupt context so
1012                  * we schedule a work item.
1013                  */
1014                 if (!get_device(&cdev->dev))
1015                         break;
1016                 PREPARE_WORK(&cdev->private->kick_work,
1017                              io_subchannel_register);
1018                 queue_work(slow_path_wq, &cdev->private->kick_work);
1019                 break;
1020         }
1021 }
1022
1023 static int
1024 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1025 {
1026         int rc;
1027         struct ccw_device_private *priv;
1028
1029         sch_set_cdev(sch, cdev);
1030         cdev->ccwlock = sch->lock;
1031
1032         /* Init private data. */
1033         priv = cdev->private;
1034         priv->dev_id.devno = sch->schib.pmcw.dev;
1035         priv->dev_id.ssid = sch->schid.ssid;
1036         priv->schid = sch->schid;
1037         priv->state = DEV_STATE_NOT_OPER;
1038         INIT_LIST_HEAD(&priv->cmb_list);
1039         init_waitqueue_head(&priv->wait_q);
1040         init_timer(&priv->timer);
1041
1042         /* Set an initial name for the device. */
1043         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1044                   sch->schid.ssid, sch->schib.pmcw.dev);
1045
1046         /* Increase counter of devices currently in recognition. */
1047         atomic_inc(&ccw_device_init_count);
1048
1049         /* Start async. device sensing. */
1050         spin_lock_irq(sch->lock);
1051         rc = ccw_device_recognition(cdev);
1052         spin_unlock_irq(sch->lock);
1053         if (rc) {
1054                 if (atomic_dec_and_test(&ccw_device_init_count))
1055                         wake_up(&ccw_device_init_wq);
1056         }
1057         return rc;
1058 }
1059
1060 static void ccw_device_move_to_sch(struct work_struct *work)
1061 {
1062         struct ccw_device_private *priv;
1063         int rc;
1064         struct subchannel *sch;
1065         struct ccw_device *cdev;
1066         struct subchannel *former_parent;
1067
1068         priv = container_of(work, struct ccw_device_private, kick_work);
1069         sch = priv->sch;
1070         cdev = priv->cdev;
1071         former_parent = ccw_device_is_orphan(cdev) ?
1072                 NULL : to_subchannel(get_device(cdev->dev.parent));
1073         mutex_lock(&sch->reg_mutex);
1074         /* Try to move the ccw device to its new subchannel. */
1075         rc = device_move(&cdev->dev, &sch->dev);
1076         mutex_unlock(&sch->reg_mutex);
1077         if (rc) {
1078                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1079                               "0.%x.%04x failed (ret=%d)!\n",
1080                               cdev->private->dev_id.ssid,
1081                               cdev->private->dev_id.devno, sch->schid.ssid,
1082                               sch->schid.sch_no, rc);
1083                 css_sch_device_unregister(sch);
1084                 goto out;
1085         }
1086         if (former_parent) {
1087                 spin_lock_irq(former_parent->lock);
1088                 sch_set_cdev(former_parent, NULL);
1089                 spin_unlock_irq(former_parent->lock);
1090                 css_sch_device_unregister(former_parent);
1091                 /* Reset intparm to zeroes. */
1092                 former_parent->schib.pmcw.intparm = 0;
1093                 cio_modify(former_parent);
1094         }
1095         sch_attach_device(sch, cdev);
1096 out:
1097         if (former_parent)
1098                 put_device(&former_parent->dev);
1099         put_device(&cdev->dev);
1100 }
1101
1102 static void io_subchannel_irq(struct subchannel *sch)
1103 {
1104         struct ccw_device *cdev;
1105
1106         cdev = sch_get_cdev(sch);
1107
1108         CIO_TRACE_EVENT(3, "IRQ");
1109         CIO_TRACE_EVENT(3, sch->dev.bus_id);
1110         if (cdev)
1111                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1112 }
1113
1114 static void io_subchannel_init_fields(struct subchannel *sch)
1115 {
1116         if (cio_is_console(sch->schid))
1117                 sch->opm = 0xff;
1118         else
1119                 sch->opm = chp_get_sch_opm(sch);
1120         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1121         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1122
1123         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1124                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1125                       sch->schib.pmcw.dev, sch->schid.ssid,
1126                       sch->schid.sch_no, sch->schib.pmcw.pim,
1127                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1128         /* Initially set up some fields in the pmcw. */
1129         sch->schib.pmcw.ena = 0;
1130         sch->schib.pmcw.csense = 1;     /* concurrent sense */
1131         if ((sch->lpm & (sch->lpm - 1)) != 0)
1132                 sch->schib.pmcw.mp = 1; /* multipath mode */
1133         /* clean up possible residual cmf stuff */
1134         sch->schib.pmcw.mme = 0;
1135         sch->schib.pmcw.mbfc = 0;
1136         sch->schib.pmcw.mbi = 0;
1137         sch->schib.mba = 0;
1138 }
1139
1140 static int io_subchannel_probe(struct subchannel *sch)
1141 {
1142         struct ccw_device *cdev;
1143         int rc;
1144         unsigned long flags;
1145         struct ccw_dev_id dev_id;
1146
1147         cdev = sch_get_cdev(sch);
1148         if (cdev) {
1149                 rc = sysfs_create_group(&sch->dev.kobj,
1150                                         &io_subchannel_attr_group);
1151                 if (rc)
1152                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1153                                       "attributes for subchannel "
1154                                       "0.%x.%04x (rc=%d)\n",
1155                                       sch->schid.ssid, sch->schid.sch_no, rc);
1156                 /*
1157                  * This subchannel already has an associated ccw_device.
1158                  * Throw the delayed uevent for the subchannel, register
1159                  * the ccw_device and exit. This happens for all early
1160                  * devices, e.g. the console.
1161                  */
1162                 sch->dev.uevent_suppress = 0;
1163                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1164                 cdev->dev.groups = ccwdev_attr_groups;
1165                 device_initialize(&cdev->dev);
1166                 ccw_device_register(cdev);
1167                 /*
1168                  * Check if the device is already online. If it is
1169                  * the reference count needs to be corrected
1170                  * (see ccw_device_online and css_init_done for the
1171                  * ugly details).
1172                  */
1173                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1174                     cdev->private->state != DEV_STATE_OFFLINE &&
1175                     cdev->private->state != DEV_STATE_BOXED)
1176                         get_device(&cdev->dev);
1177                 return 0;
1178         }
1179         io_subchannel_init_fields(sch);
1180         /*
1181          * First check if a fitting device may be found amongst the
1182          * disconnected devices or in the orphanage.
1183          */
1184         dev_id.devno = sch->schib.pmcw.dev;
1185         dev_id.ssid = sch->schid.ssid;
1186         rc = sysfs_create_group(&sch->dev.kobj,
1187                                 &io_subchannel_attr_group);
1188         if (rc)
1189                 return rc;
1190         /* Allocate I/O subchannel private data. */
1191         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1192                                GFP_KERNEL | GFP_DMA);
1193         if (!sch->private) {
1194                 rc = -ENOMEM;
1195                 goto out_err;
1196         }
1197         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1198         if (!cdev)
1199                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1200                                                      &dev_id);
1201         if (cdev) {
1202                 /*
1203                  * Schedule moving the device until when we have a registered
1204                  * subchannel to move to and succeed the probe. We can
1205                  * unregister later again, when the probe is through.
1206                  */
1207                 cdev->private->sch = sch;
1208                 PREPARE_WORK(&cdev->private->kick_work,
1209                              ccw_device_move_to_sch);
1210                 queue_work(slow_path_wq, &cdev->private->kick_work);
1211                 return 0;
1212         }
1213         cdev = io_subchannel_create_ccwdev(sch);
1214         if (IS_ERR(cdev)) {
1215                 rc = PTR_ERR(cdev);
1216                 goto out_err;
1217         }
1218         rc = io_subchannel_recog(cdev, sch);
1219         if (rc) {
1220                 spin_lock_irqsave(sch->lock, flags);
1221                 sch_set_cdev(sch, NULL);
1222                 spin_unlock_irqrestore(sch->lock, flags);
1223                 if (cdev->dev.release)
1224                         cdev->dev.release(&cdev->dev);
1225                 goto out_err;
1226         }
1227         return 0;
1228 out_err:
1229         kfree(sch->private);
1230         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1231         return rc;
1232 }
1233
1234 static int
1235 io_subchannel_remove (struct subchannel *sch)
1236 {
1237         struct ccw_device *cdev;
1238         unsigned long flags;
1239
1240         cdev = sch_get_cdev(sch);
1241         if (!cdev)
1242                 return 0;
1243         /* Set ccw device to not operational and drop reference. */
1244         spin_lock_irqsave(cdev->ccwlock, flags);
1245         sch_set_cdev(sch, NULL);
1246         cdev->private->state = DEV_STATE_NOT_OPER;
1247         spin_unlock_irqrestore(cdev->ccwlock, flags);
1248         ccw_device_unregister(cdev);
1249         put_device(&cdev->dev);
1250         kfree(sch->private);
1251         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1252         return 0;
1253 }
1254
1255 static int io_subchannel_notify(struct subchannel *sch, int event)
1256 {
1257         struct ccw_device *cdev;
1258
1259         cdev = sch_get_cdev(sch);
1260         if (!cdev)
1261                 return 0;
1262         return ccw_device_notify(cdev, event);
1263 }
1264
1265 static void io_subchannel_verify(struct subchannel *sch)
1266 {
1267         struct ccw_device *cdev;
1268
1269         cdev = sch_get_cdev(sch);
1270         if (cdev)
1271                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1272 }
1273
1274 static int check_for_io_on_path(struct subchannel *sch, int mask)
1275 {
1276         int cc;
1277
1278         cc = stsch(sch->schid, &sch->schib);
1279         if (cc)
1280                 return 0;
1281         if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1282                 return 1;
1283         return 0;
1284 }
1285
1286 static void terminate_internal_io(struct subchannel *sch,
1287                                   struct ccw_device *cdev)
1288 {
1289         if (cio_clear(sch)) {
1290                 /* Recheck device in case clear failed. */
1291                 sch->lpm = 0;
1292                 if (cdev->online)
1293                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1294                 else
1295                         css_schedule_eval(sch->schid);
1296                 return;
1297         }
1298         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1299         /* Request retry of internal operation. */
1300         cdev->private->flags.intretry = 1;
1301         /* Call handler. */
1302         if (cdev->handler)
1303                 cdev->handler(cdev, cdev->private->intparm,
1304                               ERR_PTR(-EIO));
1305 }
1306
1307 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1308 {
1309         struct ccw_device *cdev;
1310
1311         cdev = sch_get_cdev(sch);
1312         if (!cdev)
1313                 return;
1314         if (check_for_io_on_path(sch, mask)) {
1315                 if (cdev->private->state == DEV_STATE_ONLINE)
1316                         ccw_device_kill_io(cdev);
1317                 else {
1318                         terminate_internal_io(sch, cdev);
1319                         /* Re-start path verification. */
1320                         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1321                 }
1322         } else
1323                 /* trigger path verification. */
1324                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1325
1326 }
1327
1328 static int io_subchannel_chp_event(struct subchannel *sch,
1329                                    struct chp_link *link, int event)
1330 {
1331         int mask;
1332
1333         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1334         if (!mask)
1335                 return 0;
1336         switch (event) {
1337         case CHP_VARY_OFF:
1338                 sch->opm &= ~mask;
1339                 sch->lpm &= ~mask;
1340                 io_subchannel_terminate_path(sch, mask);
1341                 break;
1342         case CHP_VARY_ON:
1343                 sch->opm |= mask;
1344                 sch->lpm |= mask;
1345                 io_subchannel_verify(sch);
1346                 break;
1347         case CHP_OFFLINE:
1348                 if (stsch(sch->schid, &sch->schib))
1349                         return -ENXIO;
1350                 if (!css_sch_is_valid(&sch->schib))
1351                         return -ENODEV;
1352                 io_subchannel_terminate_path(sch, mask);
1353                 break;
1354         case CHP_ONLINE:
1355                 if (stsch(sch->schid, &sch->schib))
1356                         return -ENXIO;
1357                 sch->lpm |= mask & sch->opm;
1358                 io_subchannel_verify(sch);
1359                 break;
1360         }
1361         return 0;
1362 }
1363
1364 static void
1365 io_subchannel_shutdown(struct subchannel *sch)
1366 {
1367         struct ccw_device *cdev;
1368         int ret;
1369
1370         cdev = sch_get_cdev(sch);
1371
1372         if (cio_is_console(sch->schid))
1373                 return;
1374         if (!sch->schib.pmcw.ena)
1375                 /* Nothing to do. */
1376                 return;
1377         ret = cio_disable_subchannel(sch);
1378         if (ret != -EBUSY)
1379                 /* Subchannel is disabled, we're done. */
1380                 return;
1381         cdev->private->state = DEV_STATE_QUIESCE;
1382         if (cdev->handler)
1383                 cdev->handler(cdev, cdev->private->intparm,
1384                               ERR_PTR(-EIO));
1385         ret = ccw_device_cancel_halt_clear(cdev);
1386         if (ret == -EBUSY) {
1387                 ccw_device_set_timeout(cdev, HZ/10);
1388                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1389         }
1390         cio_disable_subchannel(sch);
1391 }
1392
1393 static int io_subchannel_get_status(struct subchannel *sch)
1394 {
1395         struct schib schib;
1396
1397         if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1398                 return CIO_GONE;
1399         if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1400                 return CIO_REVALIDATE;
1401         if (!sch->lpm)
1402                 return CIO_NO_PATH;
1403         return CIO_OPER;
1404 }
1405
1406 static int device_is_disconnected(struct ccw_device *cdev)
1407 {
1408         if (!cdev)
1409                 return 0;
1410         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1411                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1412 }
1413
1414 static int recovery_check(struct device *dev, void *data)
1415 {
1416         struct ccw_device *cdev = to_ccwdev(dev);
1417         int *redo = data;
1418
1419         spin_lock_irq(cdev->ccwlock);
1420         switch (cdev->private->state) {
1421         case DEV_STATE_DISCONNECTED:
1422                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1423                               cdev->private->dev_id.ssid,
1424                               cdev->private->dev_id.devno);
1425                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1426                 *redo = 1;
1427                 break;
1428         case DEV_STATE_DISCONNECTED_SENSE_ID:
1429                 *redo = 1;
1430                 break;
1431         }
1432         spin_unlock_irq(cdev->ccwlock);
1433
1434         return 0;
1435 }
1436
1437 static void recovery_work_func(struct work_struct *unused)
1438 {
1439         int redo = 0;
1440
1441         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1442         if (redo) {
1443                 spin_lock_irq(&recovery_lock);
1444                 if (!timer_pending(&recovery_timer)) {
1445                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1446                                 recovery_phase++;
1447                         mod_timer(&recovery_timer, jiffies +
1448                                   recovery_delay[recovery_phase] * HZ);
1449                 }
1450                 spin_unlock_irq(&recovery_lock);
1451         } else
1452                 CIO_MSG_EVENT(4, "recovery: end\n");
1453 }
1454
1455 static DECLARE_WORK(recovery_work, recovery_work_func);
1456
1457 static void recovery_func(unsigned long data)
1458 {
1459         /*
1460          * We can't do our recovery in softirq context and it's not
1461          * performance critical, so we schedule it.
1462          */
1463         schedule_work(&recovery_work);
1464 }
1465
1466 static void ccw_device_schedule_recovery(void)
1467 {
1468         unsigned long flags;
1469
1470         CIO_MSG_EVENT(4, "recovery: schedule\n");
1471         spin_lock_irqsave(&recovery_lock, flags);
1472         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1473                 recovery_phase = 0;
1474                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1475         }
1476         spin_unlock_irqrestore(&recovery_lock, flags);
1477 }
1478
1479 static void device_set_disconnected(struct ccw_device *cdev)
1480 {
1481         if (!cdev)
1482                 return;
1483         ccw_device_set_timeout(cdev, 0);
1484         cdev->private->flags.fake_irb = 0;
1485         cdev->private->state = DEV_STATE_DISCONNECTED;
1486         if (cdev->online)
1487                 ccw_device_schedule_recovery();
1488 }
1489
1490 void ccw_device_set_notoper(struct ccw_device *cdev)
1491 {
1492         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1493
1494         CIO_TRACE_EVENT(2, "notoper");
1495         CIO_TRACE_EVENT(2, sch->dev.bus_id);
1496         ccw_device_set_timeout(cdev, 0);
1497         cio_disable_subchannel(sch);
1498         cdev->private->state = DEV_STATE_NOT_OPER;
1499 }
1500
1501 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1502 {
1503         int event, ret, disc;
1504         unsigned long flags;
1505         enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1506         struct ccw_device *cdev;
1507
1508         spin_lock_irqsave(sch->lock, flags);
1509         cdev = sch_get_cdev(sch);
1510         disc = device_is_disconnected(cdev);
1511         if (disc && slow) {
1512                 /* Disconnected devices are evaluated directly only.*/
1513                 spin_unlock_irqrestore(sch->lock, flags);
1514                 return 0;
1515         }
1516         /* No interrupt after machine check - kill pending timers. */
1517         if (cdev)
1518                 ccw_device_set_timeout(cdev, 0);
1519         if (!disc && !slow) {
1520                 /* Non-disconnected devices are evaluated on the slow path. */
1521                 spin_unlock_irqrestore(sch->lock, flags);
1522                 return -EAGAIN;
1523         }
1524         event = io_subchannel_get_status(sch);
1525         CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1526                       sch->schid.ssid, sch->schid.sch_no, event,
1527                       disc ? "disconnected" : "normal",
1528                       slow ? "slow" : "fast");
1529         /* Analyze subchannel status. */
1530         action = NONE;
1531         switch (event) {
1532         case CIO_NO_PATH:
1533                 if (disc) {
1534                         /* Check if paths have become available. */
1535                         action = REPROBE;
1536                         break;
1537                 }
1538                 /* fall through */
1539         case CIO_GONE:
1540                 /* Ask driver what to do with device. */
1541                 if (io_subchannel_notify(sch, event))
1542                         action = DISC;
1543                 else
1544                         action = UNREGISTER;
1545                 break;
1546         case CIO_REVALIDATE:
1547                 /* Device will be removed, so no notify necessary. */
1548                 if (disc)
1549                         /* Reprobe because immediate unregister might block. */
1550                         action = REPROBE;
1551                 else
1552                         action = UNREGISTER_PROBE;
1553                 break;
1554         case CIO_OPER:
1555                 if (disc)
1556                         /* Get device operational again. */
1557                         action = REPROBE;
1558                 break;
1559         }
1560         /* Perform action. */
1561         ret = 0;
1562         switch (action) {
1563         case UNREGISTER:
1564         case UNREGISTER_PROBE:
1565                 ccw_device_set_notoper(cdev);
1566                 /* Unregister device (will use subchannel lock). */
1567                 spin_unlock_irqrestore(sch->lock, flags);
1568                 css_sch_device_unregister(sch);
1569                 spin_lock_irqsave(sch->lock, flags);
1570
1571                 /* Reset intparm to zeroes. */
1572                 sch->schib.pmcw.intparm = 0;
1573                 cio_modify(sch);
1574                 break;
1575         case REPROBE:
1576                 ccw_device_trigger_reprobe(cdev);
1577                 break;
1578         case DISC:
1579                 device_set_disconnected(cdev);
1580                 break;
1581         default:
1582                 break;
1583         }
1584         spin_unlock_irqrestore(sch->lock, flags);
1585         /* Probe if necessary. */
1586         if (action == UNREGISTER_PROBE)
1587                 ret = css_probe_device(sch->schid);
1588
1589         return ret;
1590 }
1591
1592 #ifdef CONFIG_CCW_CONSOLE
1593 static struct ccw_device console_cdev;
1594 static struct ccw_device_private console_private;
1595 static int console_cdev_in_use;
1596
1597 static DEFINE_SPINLOCK(ccw_console_lock);
1598
1599 spinlock_t * cio_get_console_lock(void)
1600 {
1601         return &ccw_console_lock;
1602 }
1603
1604 static int ccw_device_console_enable(struct ccw_device *cdev,
1605                                      struct subchannel *sch)
1606 {
1607         int rc;
1608
1609         /* Attach subchannel private data. */
1610         sch->private = cio_get_console_priv();
1611         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1612         io_subchannel_init_fields(sch);
1613         sch->driver = &io_subchannel_driver;
1614         /* Initialize the ccw_device structure. */
1615         cdev->dev.parent= &sch->dev;
1616         rc = io_subchannel_recog(cdev, sch);
1617         if (rc)
1618                 return rc;
1619
1620         /* Now wait for the async. recognition to come to an end. */
1621         spin_lock_irq(cdev->ccwlock);
1622         while (!dev_fsm_final_state(cdev))
1623                 wait_cons_dev();
1624         rc = -EIO;
1625         if (cdev->private->state != DEV_STATE_OFFLINE)
1626                 goto out_unlock;
1627         ccw_device_online(cdev);
1628         while (!dev_fsm_final_state(cdev))
1629                 wait_cons_dev();
1630         if (cdev->private->state != DEV_STATE_ONLINE)
1631                 goto out_unlock;
1632         rc = 0;
1633 out_unlock:
1634         spin_unlock_irq(cdev->ccwlock);
1635         return 0;
1636 }
1637
1638 struct ccw_device *
1639 ccw_device_probe_console(void)
1640 {
1641         struct subchannel *sch;
1642         int ret;
1643
1644         if (xchg(&console_cdev_in_use, 1) != 0)
1645                 return ERR_PTR(-EBUSY);
1646         sch = cio_probe_console();
1647         if (IS_ERR(sch)) {
1648                 console_cdev_in_use = 0;
1649                 return (void *) sch;
1650         }
1651         memset(&console_cdev, 0, sizeof(struct ccw_device));
1652         memset(&console_private, 0, sizeof(struct ccw_device_private));
1653         console_cdev.private = &console_private;
1654         console_private.cdev = &console_cdev;
1655         ret = ccw_device_console_enable(&console_cdev, sch);
1656         if (ret) {
1657                 cio_release_console();
1658                 console_cdev_in_use = 0;
1659                 return ERR_PTR(ret);
1660         }
1661         console_cdev.online = 1;
1662         return &console_cdev;
1663 }
1664 #endif
1665
1666 /*
1667  * get ccw_device matching the busid, but only if owned by cdrv
1668  */
1669 static int
1670 __ccwdev_check_busid(struct device *dev, void *id)
1671 {
1672         char *bus_id;
1673
1674         bus_id = id;
1675
1676         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1677 }
1678
1679
1680 /**
1681  * get_ccwdev_by_busid() - obtain device from a bus id
1682  * @cdrv: driver the device is owned by
1683  * @bus_id: bus id of the device to be searched
1684  *
1685  * This function searches all devices owned by @cdrv for a device with a bus
1686  * id matching @bus_id.
1687  * Returns:
1688  *  If a match is found, its reference count of the found device is increased
1689  *  and it is returned; else %NULL is returned.
1690  */
1691 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1692                                        const char *bus_id)
1693 {
1694         struct device *dev;
1695         struct device_driver *drv;
1696
1697         drv = get_driver(&cdrv->driver);
1698         if (!drv)
1699                 return NULL;
1700
1701         dev = driver_find_device(drv, NULL, (void *)bus_id,
1702                                  __ccwdev_check_busid);
1703         put_driver(drv);
1704
1705         return dev ? to_ccwdev(dev) : NULL;
1706 }
1707
1708 /************************** device driver handling ************************/
1709
1710 /* This is the implementation of the ccw_driver class. The probe, remove
1711  * and release methods are initially very similar to the device_driver
1712  * implementations, with the difference that they have ccw_device
1713  * arguments.
1714  *
1715  * A ccw driver also contains the information that is needed for
1716  * device matching.
1717  */
1718 static int
1719 ccw_device_probe (struct device *dev)
1720 {
1721         struct ccw_device *cdev = to_ccwdev(dev);
1722         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1723         int ret;
1724
1725         cdev->drv = cdrv; /* to let the driver call _set_online */
1726
1727         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1728
1729         if (ret) {
1730                 cdev->drv = NULL;
1731                 return ret;
1732         }
1733
1734         return 0;
1735 }
1736
1737 static int
1738 ccw_device_remove (struct device *dev)
1739 {
1740         struct ccw_device *cdev = to_ccwdev(dev);
1741         struct ccw_driver *cdrv = cdev->drv;
1742         int ret;
1743
1744         if (cdrv->remove)
1745                 cdrv->remove(cdev);
1746         if (cdev->online) {
1747                 cdev->online = 0;
1748                 spin_lock_irq(cdev->ccwlock);
1749                 ret = ccw_device_offline(cdev);
1750                 spin_unlock_irq(cdev->ccwlock);
1751                 if (ret == 0)
1752                         wait_event(cdev->private->wait_q,
1753                                    dev_fsm_final_state(cdev));
1754                 else
1755                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1756                                       "device 0.%x.%04x\n",
1757                                       ret, cdev->private->dev_id.ssid,
1758                                       cdev->private->dev_id.devno);
1759         }
1760         ccw_device_set_timeout(cdev, 0);
1761         cdev->drv = NULL;
1762         return 0;
1763 }
1764
1765 static void ccw_device_shutdown(struct device *dev)
1766 {
1767         struct ccw_device *cdev;
1768
1769         cdev = to_ccwdev(dev);
1770         if (cdev->drv && cdev->drv->shutdown)
1771                 cdev->drv->shutdown(cdev);
1772         disable_cmf(cdev);
1773 }
1774
1775 struct bus_type ccw_bus_type = {
1776         .name   = "ccw",
1777         .match  = ccw_bus_match,
1778         .uevent = ccw_uevent,
1779         .probe  = ccw_device_probe,
1780         .remove = ccw_device_remove,
1781         .shutdown = ccw_device_shutdown,
1782 };
1783
1784 /**
1785  * ccw_driver_register() - register a ccw driver
1786  * @cdriver: driver to be registered
1787  *
1788  * This function is mainly a wrapper around driver_register().
1789  * Returns:
1790  *   %0 on success and a negative error value on failure.
1791  */
1792 int ccw_driver_register(struct ccw_driver *cdriver)
1793 {
1794         struct device_driver *drv = &cdriver->driver;
1795
1796         drv->bus = &ccw_bus_type;
1797         drv->name = cdriver->name;
1798         drv->owner = cdriver->owner;
1799
1800         return driver_register(drv);
1801 }
1802
1803 /**
1804  * ccw_driver_unregister() - deregister a ccw driver
1805  * @cdriver: driver to be deregistered
1806  *
1807  * This function is mainly a wrapper around driver_unregister().
1808  */
1809 void ccw_driver_unregister(struct ccw_driver *cdriver)
1810 {
1811         driver_unregister(&cdriver->driver);
1812 }
1813
1814 /* Helper func for qdio. */
1815 struct subchannel_id
1816 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1817 {
1818         struct subchannel *sch;
1819
1820         sch = to_subchannel(cdev->dev.parent);
1821         return sch->schid;
1822 }
1823
1824 MODULE_LICENSE("GPL");
1825 EXPORT_SYMBOL(ccw_device_set_online);
1826 EXPORT_SYMBOL(ccw_device_set_offline);
1827 EXPORT_SYMBOL(ccw_driver_register);
1828 EXPORT_SYMBOL(ccw_driver_unregister);
1829 EXPORT_SYMBOL(get_ccwdev_by_busid);
1830 EXPORT_SYMBOL(ccw_bus_type);
1831 EXPORT_SYMBOL(ccw_device_work);
1832 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);